A convert's biological parents are not their parents in a halachic sense. In some senses the converting beis din is "responsible" for the convert in the way of parents. In name, at least, the ger's ...

Originally, Yizkor was said on Yom Kippur and only later was it extended to Shelosh Regalim. Why was it not said on Rosh Hashanah which is Yom Hazikkoron? It would seem more appropriate to say it then ...